This invention relates to a medical device and to an associated medical technique. More particularly, this invention relates to an endoscopic instrument and to an endoscopic method.
Flexible endoscopes are inserted into the digestive tract for diagnostic and therapeutic purposes. Endoscopes generally include a light guide for transmitting optical-wavelength electromagnetic radiation into the patient. Images are captured, typically via lenses and an optical fiber bundle or a charge-coupled device, whereby a user can visually inspect the inner walls or surfaces of the digestive tract. One common objective of endoscopic investigations in the digestive tract is to detect the presence of polyps. Where a polyp is visually detected, particularly in the colon, it should be severed, captured, and removed from the patient. Alternatively, particularly where the polyp may be a malignant cancer, the polyp may be severed and captured for extraction from the patient.
One problem frequently encountered by endoscopists is that folds of tissues in the digestive tract and particularly the colon can obscure polyps so that they can be overlooked. The colon is often collapsed and may be partially or completely draped over a lesion. In order to distend the walls of the colon, the endoscopist often pumps air into the organ. However, if too much air is introduced, the colon could perforate. Also, the patient is made quite uncomfortable with introduction of substantial amounts of air.
Another problem with visualization during an endoscopic procedure is that polyps sometimes bleed when they are severed. If the lesion site cannot be adequately visualized, it is difficult to contain and control the bleeding.